setting default number of measures per line

[Stephen Torri]

I thought that I could change the SpacingSpanner base-shortest-duration
to change how many measures there are per line. What I found was that
nothing happens when I change the value of base-shortest-duration. Here
is the controlling file is below. What is wrong?

Stephen

-----------------------

%%%%%% guitar1.ly
\include "global.ly"
\include "lyrics.ly"
\include "harmonies.ly"
\include "voices.ly"

\score {
        <<
%       \chords { \global \harmonies }
                <<
                        \new Voice { << \global \voices >> }
                >>
        >>
        \layout {
                \context {
                        \Score
                        \override SpacingSpanner #'base-shortest-duration = 
#(ly:make-moment 1 4)
                }
        }
}

\score{
<<
  \new ChordNames \chordmode {
    d
    d:7
    g
    a
  }
  \new Lyrics \lyricmode {
    \markup
    {
        \override #'(barre-type . straight)
        \override #'(finger-code . below-string)
        \fret-diagram-terse #"x;x;o;2-1;3-3;2-2;"
    } % d
    \markup {
        \override #'(barre-type . straight)
        \override #'(finger-code . below-string)
        \fret-diagram-terse #"x;x;o;2-2;1-1;2-3;"
    } % d:7
    \markup {
        \override #'(barre-type . straight)
        \override #'(finger-code . below-string)
        \fret-diagram-terse #"3-2;2-1;o;o;o;3-3;"
    } % g
    \markup {
        \override #'(barre-type . straight)
        \override #'(finger-code . below-string)
        \fret-diagram-terse #"x;o;2-2;2-1;2-3;o;" } % a
  }
 >>
  \layout{
    ragged-right = ##t
    \context{
      \Lyrics
      \override LyricSpace #'minimum-distance = #2.0
    %\override ChordNames #'minimum-Y-extent = #'(-1 . 4)
      \override Lyrics #'padding = #1.0
    }
  }
}